For example, with conventional NR (Noise Reduction) circuits, in the event that a user operates an adjustment knob thereof and sets it at a certain position, noise removal processing corresponding to the position of the knob is performed.
Now, the S/N (Signal to Noise Ratio) and frequency properties and the like of signals input to the NR circuit are not necessarily always constant, rather, it is common for these to change. In the event that the S/N, frequency properties, etc., of the signals input to the NR circuit change, suitable processing is not necessarily performed with regard to the signals input to the NR circuit in the noise removal processing corresponding to the position where the user has set the knob, and accordingly, the user needs to frequently operate the knob so that suitable noise removal processing is performed for him/herself, which has been troublesome.